1. Field of the Invention
The present invention relates a small-size zoom lens and an image pickup apparatus such as a compact digital camera equipped with such a zoom lens.
2. Description of the Related Art
Heretofore, in image pickup apparatuses such as a digital cameras and a video cameras, a high image quality, a high zooming ratio and thinning of a barrel frame have been sought.
For example, Japanese Patent Application Laid-Open No. 2005-308953 discloses a three-unit zoom lens composed of a first lens unit having a negative refracting power, a second lens unit having a positive refracting power and a third lens unit. In this three-unit zoom lens, the first lens unit is composed of a cemented lens component composed, in order from the object side, of a biconcave negative lens and a positive lens, and the second lens unit is composed of two lenses, and the third lens unit is composed of one lens. This configuration is advantageous in making the size of the zoom lens small.